Correct Prop Nut

[redmen62]

Not sure if this is a prop question or should be in the Merc I/O section, so I'll post it in both until an admin moves it accordingly

Boat is a 1968 Mark Twain, Merc160 straight 6 I believe it's the R drive

Not sure how it happened, but last weekend I lost my prop while backing out of a slip. I was able to find the prop after some surface dives, I had everything I needed to get it back on putter back to the launch. All was going great until I went to put the nut on.. I couldn't get it threaded, tried on from a neighbor and same thing, went and bought a whole new hub kit and the same thing..

So the questions is, are there different prop nut threading for older Mecruiser outdrives?

 

[Alumarine]

Best I can tell is that the part number for that nylock nut is 11-29594 and it might be coarse thread.
It appears it's different than the newer ones. Mine is .75" - 16 fine thread.

 

[indy440]

Not sure on the thread pitch, but i suspect when the prop came off it dinged the threads right at the end. Look at it real close and maybe you can fix it with a small file.

I'm not sure if this is frowned on, but i have run hundreds of hours using stainless nylock-nuts from the hardware store instead of the nut that comes in those kits. I feel like they would be highly unlikely to come off even if you didnt bend the lock taps in on the retainer plate...

 

[GA_Boater]

What indy says. Look at the thread on the prop shaft, probably a little dinged up.

On my outboard, the prop nut is a factory stainless nylock and no locking tabs. No lost prop so far.